In the IRS' General Information for Certain Information Returns, there is a list of deadlines for all the different 1099 forms starting on page 25 of the PDF.
This list tells us that both Forms 1099-DIV and 1099-INT are due to the recipient on January 31. This generally means that they need to get the form in the mail by that date, and you may receive it several days after that.
Some of the other brokerage-related 1099 forms, such as 1099-B, are due to the recipient on February 15. However, there is a note that says that the due dates for reporting forms from WHFITs are as late as March 15.
Having said that, in my experience, these forms are often delayed past these dates. For example, I received a statement this year from a broker that explained that most of their statements for accounts holding securities "that do not require year-end tax information adjustments" would be mailed by February 15, but "statements for accounts holding securities...that require year-end tax information adjustments" would be mailed by March 1, and that all remaining tax statements (including those from WHFITs) would be mailed by March 15, 2018. I'm guessing that if the broker is willing to send this information out in writing to their clients, they must believe that it is legal to delay these forms until those dates.